SQL SQRT

Returns the square root of a number — the inverse of POWER(n, 2), and a common building block in statistical calculations like standard deviation.

What & Why

SQRT(n) returns the square root. Beyond simple math, this shows up constantly in statistical formulas — standard deviation is literally defined as the square root of variance.

See How It Works

BUSINESS QUESTION

Marketing wants the square-root transform of campaign spend for exploratory analysis.

id	name	channel	spend	start_date	end_date	status	target_segment
1	Spring Launch	google_ads	55000.00	2024-01-15	2024-03-31	active	smb
2	Retention Webinar	email	45000.00	2024-02-10	2024-04-15	active	enterprise
3	Finance Retargeting	linkedin	50000.00	2024-03-12	2024-05-31	active	enterprise
4	Enterprise Search	google_ads	60000.00	2024-04-01	2024-06-30	active	enterprise

EXAMPLE QUERY

SELECT
  id AS campaign_id,
  spend,
  ROUND(SQRT(spend), 2) AS sqrt_spend
FROM marketing.campaigns
WHERE spend >= 0
ORDER BY campaign_id;

RESULT — exact output from the displayed Queryflo rows

campaign_id	spend	sqrt_spend
1	55000.00	234.52
2	45000.00	212.13
3	50000.00	223.61
4	60000.00	244.95

SQRT returns the rounded transform of each non-negative campaign spend.

Now You Try

Practice this concept

Marketing wants the square-root transform of campaign spend for exploratory analysis.

Available schema

marketing

Prefix tables with marketing.table_name.

campaign_idspendsqrt_spend

marketing.campaigns

Column	Type
id	integer
name	text
channel	text
spend	numeric
start_date	date
end_date	date
status	text
target_segment	text
legacy_id	text

query.sql

Intermediate business practice